Cleaning Up Boxwood Blight in the Landscape

Late summer through mid-fall is the most likely time to see Boxwood Blight in landscapes.  Shorter days, splashing rains, ideal temperatures from 60°-77° F, and slower drying create an environment in which the disease thrives. Be on the lookout!

Since 2011 when Boxwood Blight was first discovered in the United States, there has been a great deal of research and much has been learned regarding control and living with the disease. The earliest assumption was that any landscape infected by Boxwood Blight would need to be destroyed, however; research has shown there are many steps that can be taken to clean up Boxwood Blight properly. If certain steps are taken early, many landscapes of Buxus sp. can survive and even thrive after Boxwood Blight.

Rubber boots are easily cleaned after being worn in landscapes containing boxwood.

If Boxwood Blight is suspected:

• Take samples to testing labs and limit access to the area until results are obtained.

If you suspect the disease in the landscape, you should take great care in collecting samples by double bagging them and taking them to the local Extension office or another testing lab. The area should be roped off or temporarily fenced off until the results are obtained.

If Boxwood Blight is confirmed:

• Take great care not to further spread disease.

• Do cleanup on dry, sunny days when foliage is dry.

• Consider fungicide applications before and during cleanup to control spread.

• Wear rubber boots and disposable clothing during cleanup to lessen contamination of clothing and shoes.

• Cut and place the infected plants in a plastic bag and take care to minimize leaf litter.

• Clean up as much leaf debris as possible. Roots are not believed to carry Boxwood Blight.           

• Debris should be burned or taken to landfill with care to not let leaves escape.

• After cleanup, wash skin, launder or dispose of outer clothing, and wash boots.

• Increase airflow in and around remaining plants by thinning and removing lowest limbs.

• Do not bury debris as the disease can survive in the soil for long periods of time.

• All tools and equipment should be thoroughly cleaned when moved between different gardens or areas.

• Mulch to lessen the splashing of spores.

• Replant with cultivars that are more resistant to Boxwood Blight.

• Monitor boxwood in times of optimal conditions for new infections and flare-ups.

Crews at Saunders Brothers, inc. wear disposable clothing to help avoid introduction of Boxwood Blight that may enter the nursery on their clothing.

If Boxwood Blight is confirmed, you must be diligent and careful in cleanup. Extreme care should be taken to avoid infecting other plants. Choose a time to cleanup when it is sunny and when foliage is dry. The plant is less likely to be sporulating when foliage is dry. Consider applying fungicides to any area where you are working to kill any spores that are present.

Always wear some sort of disposable suit, like disposable Tyvek® coveralls, and rubber boots as they can easily be cleaned. If possible, put a plastic bag over the infected plant and cut the plant off at the base. Take care to catch as much leaf litter as possible. Then, clean up any leaves that fall before disturbing the soil as you do not want to incorporate diseased debris into the soil. After all debris is cleaned up, remove the roots. All debris should be bagged or covered to eliminate the possibility of it blowing or falling out. Do not compost the debris. Burning the debris is the best possible option.

The most effective way to sterilize soil is to burn any debris around the base of the infected plant.

After the cleanup is complete, remove outer clothing and launder or dispose of it. Laundering with detergent and hot water will kill spores. Boots should be thoroughly washed, and all tools and equipment should be carefully cleaned as well. Prune any other boxwood in the landscape to increase airflow to maintain dry foliage. Remove any limbs that touch the ground and might get rain splash, and be sure plants are properly mulched. Continue to monitor the boxwood during environmental conditions conducive to infection.

If planning to replant with boxwood, be sure to choose cultivars that are more resistant to the disease. Saunders Brothers, Inc. and Saunders Genetics have tested and trialed boxwood in search of varieties and cultivars that prevail against Boxwood Blight.  Buxus sempervirens ‘Suffruticosa’ (English boxwood) is the most susceptible cultivar, whereas Buxus microphylla, Buxus insularis, and Buxus harlandii species and cultivars tend to have more resistance. It is difficult to completely define groups based on species as we have found exceptions based on plant architecture and structure. Open, more upright plants tend to be less susceptible while short, compact cultivars seem to be more susceptible. NewGen Independence® and NewGen Freedom® offer strong resistance to Boxwood Blight as well as fantastic landscape appeal.

Once the landscape is cleaned and replanted, diligently monitor plants to catch any early signs of re-infection. With a combination of careful clean up, replanting with resistant cultivars, and best management practices to avoid Boxwood Blight, landscapes of Buxus sp. can continue to flourish after Boxwood Blight.

NewGen Freedom® in the field.

Partner Highlight: Overdevest Nurseries

An aerial view of Overdevest Nurseries.

Overdevest Nurseries has been a premier plant grower in the northeastern United States for nearly 70 years.  Family-owned and operated, the nursery grows more than 2,000 varieties of shrubs, trees, vines, and perennials on nearly 300 acres of land.  They provide exceptional plant material to independent garden centers and distributors within a 300-mile radius of their farm in Bridgeton, New Jersey.

John and Jean Overdevest and their young family.

John and Jean Overdevest left war-torn Holland in 1952, settling in southern New Jersey and establishing a fledgling nursery specializing in the field production of azaleas, rhododendrons, dogwoods and Japanese maples.  Their son Ed came back to the nursery in 1975 after completing his education at Cornell University in New York.  Through the 1980s and 1990s, the farm continued to expand through dedication to sustainability and the installation of water recovery basins for recycling irrigation run-off,  eventually moving into container plant production.

Ed Overdevest returning to the farm after graduating from Cornell in 1975.

The next generation, Ed and Gail Overdevest and their family.

What began as the dream of two immigrants quickly grew into a prosperous nursery operation through hard work and determination.  Now in their third generation, Overdevest Nurseries’ commitment to quality and sustainability grows stronger each year.

Overdevest Nurseries has partnered with Saunders Genetics to bring the NewGen® brand to life.  They have been crucial in trialing and evaluating NewGen Freedom® and NewGen Independence® boxwood in their growing environment.

Part of the Overdevest Nurseries team at IGC in 2015.

For more information on Overdevest Nurseries or to view their plant availability, go to their website at www.overdevestnurseries.com.  You can learn more about NewGen® growers on the Professional Grower Info page on the NewGen® website.

Being Water Smart with Boxwood

Older boxwood that are established in the landscape can survive longer periods of drought because of their more extensive and established root systems.

As we trudge through the peak of summer heat, irrigation and water is on everyone’s mind. In Central Virginia, it is common to see several weeks of unforgiving heat which can lead to dry soils and drought. Summer showers that sweep through offer some relief but rarely are absorbed into the ground enough to really help a boxwood.

The arrows show holes on the drip tape where the irrigation water escapes.

It is important to have plants in the landscape that can tolerate the ebbs and flow of the seasons. Boxwood are known for their toughness and their drought tolerance which makes them a great addition to any landscape. However, just like any plants, they have their limits, and extended periods of drought can require supplemental water. Pay close attention during these hot and dry summer months, so that boxwood do not stress. For the first 1-2 years after planting, boxwood grow best with about 1” of irrigation or precipitation a week during the summer months. Allowing the root zone to dry between irrigation events will encourage root growth. Older plants that are well established generally need minimal irrigation because their roots are deeper in the soil.

The black drip tape that runs along the mulch at the base of the plants provides water directly to the roots of the boxwood.

Drip irrigation is the ideal method for watering boxwood. Simple drip systems can be installed either on top of or under the mulch and will offer thorough irrigation without wetting the foliage. In a drip system, water seeps from the drip tape without splashing. It enters the ground without puddling and conserves water. The rate of water from drip tape is very low, typically ¼”  per hour per emitter. With almost direct access to the roots, less water is wasted thereby reducing costs and environmental impact. Drip irrigation is ideal for places where water may be limited during times of drought.

Not only is drip irrigation more cost effective and beneficial to the environment, it is better for the plant because it drastically reduces the amount of water that splashes onto the leaves of the plant. Fungal diseases such as Boxwood Blight can be spread through water splashing that often occurs with sprinkler methods of irrigation.

Drip tape is commonly used in field production because of the benefits to the plant and the reduced costs on the environment.

If a drip system is not an option, overhead watering is still acceptable, but it is important to take precautions to protect the plants. Make sure overhead watering takes place in the early morning, giving the leaves ample time to dry. Never water boxwood in the late afternoon or evening because wet foliage through the night can lead to diseases and stress on the plant. Be careful not to overwater or let water pool around the roots for too long, as it can lead to root disease like Phytophthora.

It is important to be smart when watering boxwood. Remember that they can tolerate drought but like anything, they have their limits. Boxwood that show signs of stress from either too much or too little water are unforgiving.  Pay attention to provide the appropriate amount of water and boxwood will continue to provide elegant structure to the landscape for many years to come!

July 2020: Now is the Time to Treat for Boxwood Leafminer

Adult females deposit fertilized eggs through the underside of the tender new boxwood leaves.

Although boxwood are known for their low maintenance and tend to have few pests, Boxwood Leafminer (Monarthropalpus buxi) can be a challenge for growers in the Mid-Atlantic region and around the United States. Technically a midge, not a leafminer, this pest causes damage that starts small as discolored leaves but can become severe as populations build over a period of years. Luckily, this tiny orange insect has only one life cycle per year, providing easy and effective ways to treat it.

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The life cycle begins in the early spring as the previous year’s larvae pupate and cause the boxwood leaves to discolor, blister and swell. Those pupae emerge as adults in April/May (in central Virginia), hovering only inches above the boxwood due to their weak flying abilities. Over an approximately 3-week period, adults emerge in waves to mate. Females then complete their life cycle after they lay eggs in the tender underside of the new boxwood leaves. These eggs hatch in early summer (mid-June in central Virginia) and the larvae begin the cycle of growth that will conclude the following spring.

Photo taken July 1: The young Boxwood Leafminer larvae are only visible under a microscope.

These early instars are very small, see them here compared to a pin head.

Chemical controls are the best alternative for complete treatment of Boxwood Leafminer. It is unnecessary to time a chemical application that successfully kills Boxwood Leafminer adults because the adults emerge over several weeks and live only several days, requiring multiple sprays. The larval stage provides a much longer spray window and is likely to be significantly more effective. The eggs hatch around mid-to late June in central Virginia, and the larvae are eating and growing, during the summer and fall. Research has found systemic insecticides to be effective in killing larvae until temperatures turn cold, which in some years is not until late October or early November. This strategy can provide control for up to 2-3 years as a thorough spray totally wipes out the population.

Severe blistering and discoloration are the result of heavy Boxwood Leafminer populations.

Boxwood Leafminer adults are small, orange, mosquito-like midges, that are often found hovering only inches from the foliage because they are weak flyers.

For Boxwood Leafminer control, growers have had excellent success with products in the neonicotinoid group that contain the active ingredient imidacloprid, thiomethoxam, or dinotefuran. There is a great deal of ongoing discussion regarding neonicotinoids and other chemicals and their possible effect on pollinators. Nurseries and gardeners should follow good science and alternative methods to control these pests to further eliminate use of this group of pesticides. All growers should minimize the use of any pesticide by practicing Integrated Pest Management or IPM. The goal of IPM is to effectively control a pest while minimizing negative impacts on pollinators, the environment, and employees.

Examples of insecticides listed in the Virginia Tech Nursery Crops Pest Management Guide are thiamethoxam (Flagship 25WG at a rate of 6 oz./100 gallons of water) or dinotefuran (Safari SG ¼ to ½ lb. / 100 gallons of water). These systemic products are absorbed and dispersed throughout the plant. Only one application a year is necessary to target the larvae feeding within the leaf. In central Virginia, it is recommended that the application takes place late June through mid-October.

To be noted: While Saunders Genetics has worked with nursery growers who have successfully used the pesticides listed above, no guarantees or promises, nor any opinions concerning the effectiveness or safety of these or any other pesticides are made. Always read the labels and other product information from the manufacturer and discuss the proper use and application of products with appropriate company representatives or acknowledged experts.

Although chemical control is an option on susceptible cultivars, there are also many boxwood varieties that have shown genetic resistance to Boxwood Leafminer. This genetic resistance is a defining feature in the NewGen™ Boxwood program where the goal is to provide grower-friendly plants that can thrive when faced with pest and disease pressure. NewGen™ boxwood were chosen for the program because they are more resistant to Boxwood Leafminer than most varieties currently on the market. If you are replacing or planting boxwood, consider NewGen™ varieties so that costly and troublesome sprays will not be necessary.

The New Normal: June 2020

Taking temperatures of workers as they arrive for work

By: Bennett Saunders

We all face changes every day.  We all face challenges every day.  We never know what those challenges will be.

The only constant in life is change.  But who saw this one coming?

One of the marks of a successful individual or business is the fact that he/she can face change, adapt to it, and even in some cases, seize opportunity in change.

The Coronavirus mess is disheartening.  Grandmothers, health care workers, public servants, and others are suffering.  It is truly a demoralizing event to sit through the 6:00 news at night.

On March 15, it appeared that the whole world was coming to an end.  Businesses closed.  There was no income.  There was no money flowing.  People were staying at home.

The politicians finally acted wisely.  From the lessons learned in the Great Depression, they got together (yes, that was unbelievable) and moved enormous amounts of money to individuals and businesses so that the world didn’t clam up and quit.  It appears to have worked.

This too shall pass.

The New Normal attire for pruning boxwood

Over a period of several months, we saw that things would keep going.  We were still grocery shopping.  We still were eating dinner, and as a matter of fact, we did it more as a family.  We had more time, so we made phone calls to relatives and friends and the conversations were more meaningful.  The Rat Race slowed down, and we remembered what was important.

We are hearing from business acquaintances everywhere that the Green Industry is booming.  As people spend a few more minutes in their back-porch swing, they are truly taking in the simple beauty of their gardens.  Those who are fortunate enough to be working from home have more money and more time.  The grass is getting mowed more frequently, the mulching is getting done, and everyone is excited about the new colors of hydrangea that are available when they drive down to the local garden shop.

Is this a long-term trend, or a fad?  Most experts believe that some very long-lasting and permanent changes in human behavior will result from this pandemic.  Some people will find themselves permanently working from home.  Just when we thought everybody was moving into the inner city, and their entire world would be defined by tall buildings and concrete, the Coronavirus stopped us in our tracks.  Everybody . . . yes, everybody appreciates open space, green landscapes, simple flowers, and fresh air.  This is a great time to be a part of the Green Industry!  

Frost or Freeze Damage and How to Manage It

Straw-colored foliage is typical of spring frost injury.

This year, 2020, is already in the history books as the “Year of the Coronavirus,” but boxwood growers will also remember it for some of the worst frost/freeze damage seen in decades. Central Virginia experienced two abnormally late spring frosts, one in mid-April and the other on Mother’s Day morning, May 10. Although boxwood are typically hardy evergreens that can tolerate cold, they can be susceptible to injury when extreme weather events occur. There are two different types of cold temperature-related issues. Abnormally cold night temperatures in the fall or spring result in frost or freeze damage whereas extreme cold winter temperature events result in cold injury.

Frost or Freeze Damage

Running irrigation water over the plants during a cold event can minimize frost or freeze injury.

The terminology frost damage usually refers to a rather mild frosting of plants in the fall or spring, generally resulting in light die-back in the tops of boxwood. Freeze damage occurs at the same time but describes more severe damage as a result of colder temperatures or more prolonged cold temperatures. In the mid-Atlantic area of the United States, the damage from these weather events can occur in the fall from October through early November, or in the spring from late March through early May. The resulting damage is a “burning” of the most tender foliage, usually the tips of the newest growth, of the boxwood. The damage occurs when the temperature gets below 30 degrees Fahrenheit, with the worst damage occurring during a freeze event when the temperatures get into the low to mid 20’s. An extreme freeze event, with temperatures in the low 20’s in the fall or spring, can cause bark splitting, with resulting dead limbs of perhaps even the entire plant.

Frost blankets are specifically designed to be placed over plants during cold weather events. The fabric is breathable to prevent diseases, but warm enough to protect tender boxwood.

The discoloration and spotting on this Buxus microphylla cultivar could be mistaken for Boxwood Blight but is actually a common sign of frost or freeze damage.

In the fall, the extent of the damage of a frost/freeze event is related to the temperatures leading up to the cold temperatures, with the worst damage occurring with a very warm fall followed quickly by a severe and early frost or freeze.

In the Spring, the extent of the damage is related to the development of the new growth in the boxwood, with the worst damage occurring with a very early and warm spring fully pushing out the new growth of the boxwood, followed by an abnormally cold night.

Partner Highlights: Prides Corner Farms

The hillside at Prides Corner Farms - Photo credit: Prides Corner Farms

Prides Corner Farms, a family owned nursery in Lebanon Connecticut, has spent the past several decades establishing itself as a premier grower in the Northeastern United States. Their incredible product diversity and their exceptional customer service has positioned them as an industry leader. With a company goal of not only providing exceptional products, but being a business partner to their customers, they help their customers grow and become more profitable.

Mark Sellew circa 1990 - Photo credit: Prides Corner Farms

From humble beginnings in 1979, Peter Sellew began Prides Corner Farms on 50 acres of land with a handful of greenhouses. His son Mark Sellew joined the business shortly after in 1980, fresh from his graduation from Cornell University in Ithaca, New York. Mark brought back with him big dreams of becoming a major grower in the Northeast. Over the next decade they worked towards this goal, creating a team with the experience and knowledge to take them over the million-dollar mark.

Peter and Mark envisioned a company that did not just sell plants but positioned themselves as a business partner for their customers, working together to find solutions to the problems they faced. Mark assumed complete ownership in the late 1980s and continued to pursue that goal. Through the 1990s and 2000s, Prides Corner became an industry leader, providing diverse product selection, innovative marketing and branding, and state of the art logistics to deliver these outstanding products to their customers.

Today the Prides Corner team continues to pursue innovation and success in their goal to be the best partner for their customers.

American Beauties in the Native Plants garden in the Arboretum - Photo credit: Prides Corner Farms

Plants on display at Pride’s Arboretum - Photo credit: Prides Corner Farms

Prides Corner Farms has been an essential partner, working with Saunders Genetics to trial and evaluate NewGen Freedom® and NewGen Independence® at their nursery and in their trial gardens. They have been a crucial part of establishing this program and introducing these problem-solving plants to the industry. To learn more about NewGen™ growers or if you have interest in becoming one, check out the Partners page. For more information about Prides Corner or to find out their availability of NewGen™, check out their website.

A Time to Plant Boxwood

NewGen Freedom® mixing with some bright flowers in a perennial bed.

With many people hunkered down at home during the COVID-19 outbreak, everyone is finding ways to de-stress and pass the time while staying healthy. Most nurseries and garden centers remain open as essential businesses and provide many people a safe way to celebrate the season. Nurseries and garden retailers are adapting to ensure customer safety, all while providing the plants and supplies needed to create and maintain at home gardens and landscapes. Spring marks the perfect time to plant many varieties of trees and shrubs, including boxwood. Time to take a break from the news, or binge watching a new show, and spend some time soaking up Vitamin D in the garden!

Boxwood tolerate pruning well and can make beautiful, intricate hedges.

Boxwood offer many benefits to new and established landscapes and are known for their easy maintenance. With few pests and diseases affecting them, most varieties and cultivars require annual pruning and minimal supplemental nutrients. These timeless evergreen shrubs are characterized by their longevity, come in many sizes providing versatile shape and structure to any landscape for ages to come.

Boxwood lining a walkway to a front door.

Though boxwood require minimal care, there are a few things to consider before planting, beginning with site selection.

Start by checking the soil to be sure it provides good drainage. Boxwood, like many plants, don’t enjoy having “wet feet” or their roots are sitting in soil that is regularly saturated with water. Soil with good drainage provides an environment for healthy roots and overall plant growth. Boxwood prefer a soil pH that is more neutral, preferably between 6.5-7.0. If your soil pH is below that, amendments such as dolomitic lime or other fertilizers can be added to raise the pH.

When selecting a site for your boxwood, it is also important to consider sun exposure. Many boxwood prefer some shade, but different varieties and cultivars can handle different exposures. There are many varieties and cultivars of boxwood that offer different shapes, sizes, colors, and even pest and disease resistance! Now that you’ve found the perfect location, it is time to decide which cultivar fits your needs best. Resources such as the Saunders Brothers Boxwood Guide offer lots of information about many of the varieties on the market. There is also detailed information about NewGen Freedom® and NewGen Independece® under the NewGen™ tab on our website.

NewGen Independence® and it’s dark shiny foliage catching the last of the afternoon sun.

Once you’ve selected the proper location and best variety for your landscape, it’s time to plant! Start by digging a hole approximately twice as wide as the root ball, and deep enough that about 2” of the original root ball is above the soil line. This is often referred to as “planting high,” helping with drainage. Make sure the root ball is sitting on undisturbed soil, so that the soil won’t settle and reduce drainage later. See the diagram below.

After planting and covering the root ball, make sure to irrigate well. Many experienced gardeners will tell you the first watering after planting is the most critical! Be sure to fully soak the recently planted boxwood, being diligent that the water soaks all the way through the root ball. Afterwards, periodic watering on an as-needed basis is best. Monitor for adequate moisture, approximately 1” of precipitation or irrigation a week for the first year. For more detailed information about site selection and irrigation, check out the highlighted article.

Boxwood make great hedges around container and vegetable gardens.

Finally, once your new boxwood is planted and watered in, it is time to mulch. Mulching boxwood used to be discouraged, however new research findings have proven that mulching boxwood is an essential part of maintenance. Not only does mulching reduce weeds, regulate soil temperature, and encourage proper soil ecology, it also helps prevent Boxwood Blight. A layer of mulch about 1” thick is sufficient.

Although many may be feeling discouraged as we adapt to life at home for the next few weeks, it is important to look at this as an opportunity to start something new or revitalize an old landscape. Getting your hands dirty with some fresh soil as you add your beautiful new boxwood to your landscape is sure to bring a smile to your face and hope in your heart. Take this time to spruce up your green space with a landscape you will cherish for years to come.

Different cultivars of boxwood can be used together to make elegant designs.

For more garden inspiration, check out the Boxwood Photo Garden.

A Return to Sacred Ground

By: Bennett Saunders

March 27, 2020

Marshall and a native brook trout.

The nursery boxwood dig list on Friday was very lean.  Business was dead.  The Coronavirus had caused the entire country to shut down.  Everybody was staying at home.  Even church was closed.  There was nothing to do this weekend.

My 25-year-old son, Tye had asked me to go trout fishing with him.  His boss had told him to stay at home in Charlotte, North Carolina, and rather than stay alone in his apartment, he had decided to come back to Piney River, Virginia.  He had been home for 10 days working remotely with the WiFi in our home.

I hadn’t been trout fishing with him, seriously...ever.  As a young teenager, my dad had taken me fishing to this remote native trout streams as a rite of passage.  As I do the math, I absolutely cannot fathom that was 45 years ago.  I had told my sons for years we should go up there fishing.  But it was too far to walk.  It would take a WHOLE DAY.  I had other things to do.  I didn’t have the time. 

But now I did.

Bennett, Tye, and Sawyer on the hike into the remote fishing grounds.

Tye, in turn, invited his older brother Marshall to go with us, and it became a family affair which even included our dog, Sawyer.  As we stopped to catch our breath on the rugged 2-mile hike into the remote mountain trout stream, I gave them the family history lesson. 

It is difficult to imagine, but this rugged mountain land was once farmed by my great-grandfather’s family.  There were piles of rocks and terraces everywhere, some old “fields” no larger than an average room in a house.  They raised tobacco on these terraces in the mountains. 

My great-grandfather Paulus Powell Massie, a Baptist preacher, was born and raised in these mountains.  Born in 1851, he was but 10 years old when the Civil War broke out in 1861.  His four older brothers went off to fight the Yankees.  One was laid to rest at Gettysburg as a member of 19th Virginia Infantry in Pickett’s charge on July 3, 1863.  One was wounded at the battle of Chancellorsville, recovered, but succumbed to dysentery and died in 1864.  Two brothers fought vain battles for the Southern Cause for four years and were lucky enough to walk home from Appomattox. 

Left to right: My great-grandfather, Rev. Paulus Powell Massie, his wife Emma, and Emma’s father David Staples Woodson (another Civil War Veteran) circa 1930. English boxwood in the background.

Family lore has it that my great-grandfather’s family raised huge tobacco crops in these mountains during the Civil War.  They stored tobacco under a huge rock on the side of the mountain but didn’t sell it until after the Civil War because Confederate money was worthless.  When they did sell, the brothers and their father made enough money from the crop to make a down payment on the boxwood farm that I now live on.

I thought it was tough now!  It is interesting to hear of the toils of our ancestors.  During their lifetime, they struggled with inferior farmland, a Civil War that took two brothers to their death, constant sickness with limited medical help, and then lean times during Reconstruction.  It puts the Coronavirus into perspective.  We will get through this, and we will be stronger in the end.

I have now passed this rite of passage with my sons.  The mountains were brilliant, the stream spectacular, and the fishing… do we really have to catch fish?  To leave civilization and the Coronavirus for a weekend was a breath of fresh air.  The weekend made me remember what is important in life.  It brought my family together for a memorable weekend.  I am ashamed that it took 45 years and a deadly virus for me to take my boys to this sacred ground.

Beware, fish!

APHIS Takes Step to Slow Possible Boxwood Tree Moth Introduction

An example of the damage caused by the Boxwood Tree Moth.

There is good news from the Animal and Plant Health Inspections Service (APHIS) this month! APHIS has approved the federal order restricting the importation of Buxus, Euonymous, and Ilex from Canada, in an effort to reduce the possibility of introduction of the Boxwood Tree Moth to the United States. This amendment is an important step in the right direction to protect boxwood and other crops from infestation.

Although the Boxwood Tree Moth has not been found in the United States, it has devastated boxwood production in Europe and was identified in Ontario, Canada in October 2018. Since then, Canada has been working to mitigate the spread of the pest.

This recent amendment, effective as of March 3, 2020, states that, “the importation of all propagative plant material, except seeds, of certain hosts of box tree moth are Not Authorized Pending Pest Risk Analysis.” It also states new requirements for shipments imported from Canada, including phytosanitary certificates with an additional declaration certifying that the plants fulfill certain requirements. These plants must have been produced in a facility or area recognized by CFIA as free of box tree moth or, the shipment has been officially inspected and found to be free of the pest.

Steps like these drastically decrease the movement of possibly infected material. Unfortunately, without protections like these, invasive species can quickly spread and cause devastation. Taking the necessary actions early in the process drastically reduces the likelihood of an introduction of this pest.

Both the larvae (caterpillar) and pupae stages of the Box Tree Moth, characterized by their bright green color with black stripes.

The adult form of the Box Tree Moth with the distinct white “cresent” shaped spot on each wing.

Tips on Pruning Boxwood

This tall boxwood with some winter color and shaggy branches before its annual pruning.

Pruning is an essential part of plant upkeep and an excellent method of preventative maintenance for both young or more established plants. Most ornamental plants benefit from annual pruning, and boxwood are no exception. There are many benefits both for the overall look and health of the plant, making it important to establish a pruning schedule for boxwood in any landscape.

One of the most common reasons to prune is to shape up boxwood and provide a cleaner more defined appearance. Boxwood are characterized by the structure they provide to gardens, and pruning helps to maintain a clean shape. Early spring, before boxwood begin to flush, is the best time of year to prune. Any old winter color, or tips that have been burned over the winter season, can be trimmed away and will disappear after the spring flush.

Not only is it important to prune, but proper pruning techniques are crucial to long-term success with boxwood and may differ slightly with each cultivar. It is important to choose the correct cultivar to avoid the need for excessive pruning. Before and during annual pruning, proper sanitation of necessary tools is important. Any tools should be properly cleaned with alcohol, bleach, Lysol® or some other disinfecting solution before and after working with boxwood to lessen the possibility of spreading disease.

Buxus ‘Dee Runk’ before annual pruning.

The same Buxus ‘Dee Runk’ after annual pruning.

As mentioned above, the best time to prune boxwood is in the late winter to early spring, before the plant breaks dormancy and begins flushing. This is typically late February to mid-March in central Virginia. Late winter/early spring pruning minimizes the time between pruning and new growth as well as stimulating a strong spring flush. Also, Boxwood Blight tends to be much less active in cold temperatures.

This freshly pruned boxwood had its winter color pruned off and is ready for its spring flush!

If you are looking for a more manicured look, some gardeners like to prune in late spring, after the spring flush to achieve a more formal shape. Mid-summer and early fall pruning stimulate late fall growth that may be burned by frost or early winter freezes. Waiting until early winter might not be detrimental; however, it leaves pruning scars on the leaves until the spring flush is initiated.

Cultivars that are more dwarf or have very tight habits benefit from annual thinning to open up the inside of the plant. Thinning is typically done by reaching into the plant and breaking or cutting out branches with hand pruners. These branches can be 6-10 inches long on larger cultivars, or only a couple of inches on a dwarf cultivar. This will leave pockets or holes in the plant for air and sunlight penetration. Using hand pruners will result in a cleaner cut and lessens the possibilities of disease introduction. Any cultivars that are sheared regularly will benefit from thinning to lessen disease susceptibility.

Larger and more vigorous cultivars are generally tolerant to shearing or more radical pruning techniques. Use loppers or shears to drastically reduce overall plant size on vigorous plants, taking care to leave one-half to two-thirds of the foliage undisturbed. This foliage will produce energy the plant needs to recover. The plant should develop new foliage along the bare stems. Full recovery may take several seasons. Plants that require more drastic pruning may need to be pruned over several years to reduce the overall size in steps and not jeopardize the plant’s health. To minimize radical pruning, do not select large cultivars for applications where small cultivars would be more suitable.

Large Pruning shears can be used for larger, more vigorous varieties.

Establishing pruning as part of the overall maintenance of your boxwood encourages healthy growth on both young and more established plants. Whether it is to neaten the plants appearance, rejuvenate an overgrown shrub, or help maintain a healthy environment, annual pruning is a key part of your success with boxwood.

Jan. 2020: Saunders Genetics Announces European Partner

Bennett Saunders (left) and Peter Kroes (right) at MANTS 2020.

Saunders Genetics, LLC of North America and Dutch company van Vliet New Plants B.V. have agreed to a joint venture that begins a process that will lead to the eventual sale of Saunders Genetics’ patented NewGen™ Boxwood in the European consumer market. Bennett Saunders, General Manager, Saunders Genetics, and Peter Kroes, co-owner of van Vliet New Plants have taken the initial step of supplying plant material to select European growers for trialing over the next 12-18 months. Anticipated results of the plant trials will open the door for licensed growers to produce and distribute NewGen™ to European consumer gardeners.

Saunders Genetics introduced the NewGen™ Boxwood brand to the North American market in 2019 to much fanfare due its improved genetics that demonstrated greater tolerance of Boxwood Blight, higher resistance to Boxwood Leafminer, and WOW factor in the garden and landscape. At this time, 22 North American licensees have signed on to grow the first two plant introductions, NewGen Independence® and NewGen Freedom®. European growers are seeing the potential of NewGen™ Boxwood as a means to combat the devastation of blight that began in Europe and migrated to North America in 2011. Saunders Genetics was created not only to combat Boxwood Blight, but as a boxwood solution taking into account many years of trials and research on boxwood insects, diseases, and cultural factors.

van Vliet New Plants has been chosen as Saunders Genetics’ European connection for the introduction and management of NewGen™ in the Euro trade and consumer marketplace. The trialing process and building of production leading to consumer sales is expected to take 2-3 years. van Vliet New Plants with its global network is a recognized and proven leader in the protection, control, marketing, and management of new plant varieties.

“We believe NewGen™ Boxwood from Saunders Genetics has tremendous potential for the European market,” said Peter Kroes, co-owner at van Vliet New Plants. “The bar has been raised in the effort to find solutions to Boxwood Blight and we’re excited to be at the forefront in bringing this new generation of plant material to our audiences. Beyond blight, our association with Saunders Genetics’ long-range goal of elevating boxwood across a range of attributes and performance signals a bright future for this foundational plant.”

“We’re very pleased to be working with Peter and van Vliet New Plants in exploring the opportunities of the European market,” said Bennett Saunders, general manager of Saunders Genetics and co-owner

Feb. 2020: Third International Summit on Boxwood Challenges

The NewGen™ and Saunders Brothers teams at the Third International Summit on Boxwood Challenges, hosted by the American Boxwood Society.

Last month the American Boxwood Society hosted its Third International Summit on Current Boxwood Challenges. Over 140 people heard from researchers and growers from Europe, Canada and the United States who discussed the latest research on Boxwood Blight and the Boxwood Tree Moth. This one-day event was hosted at the National Agricultural Library in Beltsville, Maryland.

Although the Boxwood Tree Moth has not been found in the United States, it has devastated boxwood production in Europe. The morning session of the event began with research on the biology of the moth, determining the invasive pathways that introduced the moth to Europe, concluding that the pest was originally introduced from eastern China to Germany in 2007 and has since spread significantly over Europe. Most of the spread has been from the transport of infected plant material, with some movement through native boxwood forests. The moth was found in the United Kingdom in 2008 and has since spread around the southern parts of the country. Chris Poole, the Chairman of the European Boxwood & Topiary Society, shared management strategies being utilized in the United Kingdom and around Europe against the moth.

The morning session finished with speakers from North America, focusing on what the Canadian industry is doing to monitor and prevent the spread, and how the U.S. can prepare against the moth. First identified in Ontario in October 2018, OMAFRA (similar to U.S. Extension) has diligently been monitoring and treating the pest as it appears. Using many of the same tactics that have been effective in Europe, most infections are low to moderate, with less than 10% considered severe. In the United States, using pheromone traps for detection and diligently spreading the word about this potentially invasive species can aid in catching the moth early. In the event that it is found, there are methods of control already available. Researchers are aware of the pest and are focusing efforts to learn from those already affected in order to prevent the introduction of Boxwood Tree Moth to the United States.

The afternoon focused on Boxwood Blight starting with a recap of what is known about the disease and ways to treat and prevent it. Mary Ann Hansen, who works in the Plant Disease Clinic at Virginia Tech, has many years’ experience identifying Boxwood Blight. She shared information about the biology of the disease, how to identify it, and how to clean it up in the event of an infection. There are many tools available to the public about Boxwood Blight, including the Virginia Boxwood Blight Task force website.

The event finished with several presentations on further research being done around the U.S. There are many projects in the works focused on learning new and effective control strategies. Projects range from breeding programs to biocontrol studies to thermotherapy, all being done at many universities around the U.S. There is still no silver bullet in preventing or treating Boxwood Blight, but the is a light at the end of the tunnel as much of the research proves positive. One of the recent studies showed a decrease of Boxwood Blight lesions by 97% just from adding a layer of mulch. You can read more about that study here. As research continues, we only get more positive that as an industry we can overcome this challenge.

If you’d like to learn more about events like these, check out the American Boxwood Society’s website.

Botany of the Boxwood Flower

By: Keith Yoder, Professor Emeritus of Plant Pathology, Virginia Tech

Boxwood flower buds.

Figure 1. Dormant boxwood flowers. Note terminal buds, right, and axillary buds, center left

Boxwood typically blooms in February and March in central Virginia. The dormant flowers appear generally globular (Figure 1), but are actually flower clusters composed of a single female (pistillate) flower tightly surrounded by as many as six male (staminate) flowers. They are arranged along shoots as axillary clusters or at the shoot tip as terminal clusters.

With warming temperatures in late winter, swelling buds signal the onset of flowering. The female flower has 4 to 7 or more sepals at its base and a single three-celled ovary topped with three short styles with two-lobed stigmas (Figure 2). The ovary has three locules, each with two ovules. Each ovule is capable of developing into a seed, potentially yielding six seeds per flower. The male flowers have four sepals arranged as two opposite pairs and four stamens, each opposing a sepal, composed of a thick filament topped by a two-celled anther.

Figure 2. Emerging pistils of female flowers.

Figure 3. Developing anthers of male flowers.

As the flowers develop in the spring, the tips of the three pistils begin to protrude from the central female flower bud (Figure 2), and they expand further into the two-lobed stigmas where the pollen is received. Meanwhile, yellowish-green anthers emerge from the male flowers (Figure 3). The initially plump two-celled anthers begin to split (dehisce) longitudinally and shed pollen (Figure 4), which is deposited on the exposed stigmas. The inconspicuous flowers lack petals and, when viewed from some distance, much of the observed color is due to the appearance of the anthers on a heavily-blooming plant.

Figure 4. Male flower anthers shedding pollen.

Figure 5. Developing fertilized female flower. (Male flowers had been removed to prevent self-pollination for controlled breeding purposes).

After pollination, the fertilized ovaries begin to expand and develop three distinct horns on the immature green capsules (Figure 5). After they mature in mid-summer, the capsules split longitudinally (Figure 6) and open suddenly to forcibly discharge the shiny black seeds (Figure 7).

Figure 6. Capsule from which seeds have been discharged.

Figure 7. Seed capsule with discharged seed.

The above descriptions of the flowers and flowering process are ‘typical’, but there are some exceptions in structure and development. For example, we have observed ‘National’ with only female flowers in the American Boxwood Society Memorial Garden, State Arboretum of Virginia, Blandy Experimental Farm, Boyce VA. The time of development may vary without explanation. After seeing flowers with anthers of an unidentified variety open in Winchester VA in early December 2019, we scouted the plantings at Blandy and found ‘Miss Jones’ and ’Tall Boy’ also with anthers exposed. One would not expect flowers pollinated in December to develop through mid-winter.

References:

Batdorf, L. R. 2004. Boxwood; an Illustrated Encyclopedia. The American Boxwood Society, Boyce VA. 343 pp.

Batdorf, L. R. 2005. Boxwood Handbook, A Practical Guide, 3rd Edition. The American Boxwood Society. Boyce VA. 123 pp.

These publications are available at:  https://boxwoodsociety.org/abs_publications.html

Jan. 2020: Highlights from the Winter Trade Shows

The winter trade show season offers many regional shows across the US. We were excited to participate again in both the Mid-Atlantic Nursery Trade Show (MANTS), and NCNLA’s Green and Growin’ show. This year marks the official launch and availability of NewGen™ Boxwood and these shows provided a great opportunity to meet many new faces and share the message of NewGen™.

MANTS:

The NewGen™ Team in the MANTS booth.

We kicked off the new year in Baltimore, Maryland at the Mid-Atlantic Nursery Trade Show. Celebrating their 50th anniversary, the show brings in thousands of people from all aspects of the green industry and from all over the globe. It is one of the leading industry events that showcases everything from nursery stock, to the latest, innovative technology.

This year we were excited to welcome growers, retailers and landscapers into our booth to learn more about the program. Many new faces stopped by to see and interact with the plants and learn more about their benefits. Attendees could interact with NewGen Independence® and NewGen Freedom® on display at our five partner growers’ booths, Saunders Brothers Nursery, Willoway Nurseries, Overdevest Nursery, Prides Corner Farms, and Sheridan Nurseries.

MANTS is a big show that attracts industry members from all over the globe, including our European partner Peter Kroes with van Vliet New Plants. We are excited about this partnership and look forward to sharing these problem-solving plants with the European market.  

Bennett Saunders and Peter Kroes at the NewGen™ booth.

We set aside some time Wednesday after the show to have a brand meeting with our network of growers. This provided a time to check in and share our plans for the program over the next year. We are excited about what this year has in store as our network of growers expands to provide plants to more regions of the U.S.

Green & Growin’:

After MANTS we headed south to Greensboro, NC for the NCNLA Green & Growin’ show. A slightly smaller show, this event caters to the South Eastern market of the US,  from Virginia down the coast and around the gulf. This weeklong event has classes and workshops in the beginning of the week, followed by a two-day trade show. Along with Saunders Brothers, many of the NewGen™ network growers were excited to talk about the program with the attendees of the event.

The NewGen™ booth at the Green & Growin’ Show.

The winter trade shows are a light in the middle of the long cold winter to remind us that spring is right around the corner. It was great to reconnect with many friends, as well as meet many new faces! As spring approaches, we are looking forward to the first NewGen™ boxwood hitting the markets. If you are looking to get some on order, check with our Partners to see what’s available in your area!

Partner Highlights: Willoway Nurseries

Willoway Nurseries, a third generation, family owned business is one of the largest wholesale growers in the Midwest and ranks in the top 40 growers nationwide. Located outside of Cleveland, and just south of Lake Erie, they provide quality plants to the Midwest and across the US.

From humble beginnings, Les Demaline at age 18, became the sole proprietor of Willoway Nursery in 1954. Named after a row of willow trees that grew along his parent’s house, the nursery began with Les growing propagated geraniums, taxus, and other evergreens plants in hot-bed houses.

Through the years the nursery has grown substantially, expanding to multiple farms, covering approximately 550 acres of field production and 450 acres of container plants, including 32 acres of climate-controlled greenhouses. Willoway has a diverse inventory with over 2,000 varieties of quality trees, shrubs, perennials, annuals, and tropical plants, and participates in many of the biggest national brands.

Willoway Nurseries has been essential in working with Saunders Genetics to trial NewGen Freedom® and NewGen Independence® at their nursery. Last year we joined WIlloway in their booth at Cultivate to announce our first two plant selections. You can read more about their nursery here.

Our partners are an essential part of who we are, we are excited to work with Willoway and several other growers to launch this problem-solving line of boxwood. To learn more about our partners, or if you have interest in becoming a partner, check out the partners page on the website.

Jan. 2020: The Start of the New Year

As the decade comes to a close, we set our sights to the future and the opportunities presented in the new year.   Last month we looked at the official launch of the NewGen™ brand in 2019. Now as we enter 2020, we share the plans we have and how we hope to expand and connect with the industry.

Events:

Trade events and shows provide a place for many members across the industry to connect with one another and showcase the newest and most exciting products. There are many shows all over the world that cater to their region, and we are excited to participate in a few of them. The winter show season begins with one of the biggest industry events in Baltimore, MD. The Mid-Atlantic Nursery Trade Show (MANTS) will be held next week at the Baltimore convention center starting Wednesday Jan 8th until Friday Jan 10th. This show brings in a whole spectrum of industry members from the Mid-Atlantic and around the US. Last year we officially launched the NewGen™ brand at the show. We are excited to participate again, come visit us at booth 174! You can also look for NewGen™ at our partners booths around the show.

NewGen™ on display at Saunders Brothers Nursery’s booth 424.

After MANTS we will head to North Carolina to participate in NCNLA’s Green & Growin’ show in Greensboro. The show will be Thursday and Friday, Jan 30th -Feb 1st. Come visit us at booth is 529 we, look forward to seeing you there!

NewGen™ on display at Cultivate ‘19

Later in the year we will participate at the AmericanHort event, Cultivate in Columbus, OH. The show is in July and includes educational events along with a trade show. We are excited to participate in other regional shows as the schedule allows and will update you all as we add them to the calendar.

Educational Events:

Bennett Saunders giving a presentation at the First Annual NewGen™ Field Day.

One of our major goals with NewGen™ is to provide up-to-date research and information to the industry about Boxwood and Boxwood related issues. Part of that includes participating in events where we can share this knowledge with the industry and the public. Our team is excited to give presentations at events such as the SNA conference in Baltimore, MD, and the Boxwood Health Conference in Aurora, OR. We are also excited to sponsor and promote other events such as the American Boxwood Society’s event: The Third International Summit on Boxwood Challenges. Events like these bring in researchers from all over to share the most up to date information on boxwood challenges.

Plant Availability:

Starting this year, NewGen™ Boxwood will officially be available for sale from our five partner growers. Our partners include: Overdevest Nurseries in NJ, Prides Corner Farms in CT, Saunders Brothers Nursery in VA, Sheridan Nurseries in Ontario, and Willoway Nurseries in OH. Make sure to check out their websites and contact their sales teams to see when their plants will be on availability.  We are excited to see over 75,000 plants available to growers, landscapers, and retailers this year!

Other ways to stay connected:

As the year progresses, we are excited to continue to develop our digital presence through our website, social media, and other platforms. Continuing to connect with the industry remains a priority as we share the message of NewGen™ Boxwood. We will continue to utilize our website and newsletters to share information and research about boxwood as well as any news about the program.

With an exciting year behind us and an ambitious year ahead of us, we are looking forward to 2020 and the start of a new decade. Happy New Year from all of us at NewGen™

Dec. 2019: Looking Back at the First Year of NewGen™

December marks the end of a productive year and encourages reflection as we look back at 2019. This year marked the official launch of the NewGen™ Boxwood brand and the unveiling of its first two introductions, NewGen Freedom® and NewGen Independence®. These plants will become officially available spring of 2020, from our 5 partner growers, Overdevest Nursery in NJ, Prides Corner Farms in CT, Saunders Brothers, Inc. in VA, Sheridan Nursery in Ontario, and Willoway Nursery in OH. With the expectation of a promising future, lets recap on how we got to where we are.

Winter:

We started off the year with our first official announcement of the NewGen™ brand at the Mid-Atlantic Nursery Trade Show (MANTS) in Baltimore, MD. With over 10,000 participants at the show, this was a great opportunity to connect with fellow industry members and share what we have been working on. Over 70 years in the making, it was exciting to finally share our answer to many issues facing boxwood in today’s world. Our team connected with other growers and worked to recruit licensees to expand the brand to reach consumers all over the US and Canada. After MANTS we headed to Greensboro, NC for the Green & Growin’ show to connect with more growers and share our story.  

Winter was also a busy season as we launched our official website to share our message and bring the industry the most up to date information on boxwood. Our goal is to grow this website into a tool that can be utilized by all seeking information on boxwood cultivar care, research, history, and other topics of interest.  

Spring:

Spring is always a busy time of year in the green industry and that rang true for NewGen™ as well. Building from the excitement of the winter trade shows, NewGen™ and Saunders Brothers, Inc. were featured in several industry-focused media channels. The research Saunders Brothers has done on Boxwood Blight and Boxwood Leafminer (that lead to the creation of the brand), picked up attention from publications like Nursery Management, Grower Talks, Greenhouse Grower, and even Garden & Gun magazine.

March marked the beginning of our monthly e-newsletter, that allows us to share with consumers news about NewGen™, share tips on care, and the latest reports on boxwood research.

Spring also gave us the chance to further relationships made at the trade shows and industry events, encouraging many growers to join the NewGen™ network. We are grateful to be working with wonderful, like-minded growers in the U.S. and Canada to provide NewGen™ Boxwood to consumers everywhere.

Summer:

Things started heating up this summer with the official unveiling of the first two selections of the NewGen™ brand. At the Cultivate event in Columbus, OH, NewGen Independence® and NewGen Freedom® made their debut and received the Retail Choice award from the Garden Center Group. These two introductions mark the culmination of years of testing and trialing, and we are proud to have been chosen out of 70 participants. Selected for their disease tolerance, pest resistance, WOW factor in the landscape, and grower friendliness, these plants truly provide solutions for many of the struggles gardeners face today.  

In addition to introducing the first two NewGen™ selections, we produced a video that shares our story of where we began, how we got here, and what our hopes are for the future. So much of what we do is rooted in our story and we want to share that message with both growers and consumers. The passion to understand the problems faced by boxwood years ago unwittingly sparked the creation of the problem-solving plants we have today.

Fall:

Temperatures cooled, leaves began to change colors, and the dust from the exciting year began to settle. We took this opportunity to open our doors and invite both network and partner growers to Virginia to share more about the NewGen™ program. In October, Saunders Brothers welcomed growers from all over the US to participate in the first annual NewGen™ Field Day, providing an opportunity to build relationships, share ideas, and learn more about boxwood production.

We reflect on 2019 and are grateful to all of those that have made it such a successful year. We thank our partner growers for working with us as we launched our brand. We appreciate the grower network that has joined us to produce this exceptional line of plants. We are especially thankful for the years of dedication to boxwood research that Saunders Brothers has pursued, culminating in the creation of Saunders Genetics and the NewGen™ brand.

With a successful first year behind us, we focus our sights on 2020., when NewGen™ will officially be available to be planted in gardens and landscapes everywhere. Boxwood have faced many setbacks in the past decade, but NewGen™ is here to show you that growers everywhere can succeed with boxwood. The boxwood revolution has officially begun!

Boxwood Holiday Decorations

Boxwood have been a cherished landscape ornamental for centuries but are also appreciated by many for the charm they can bring around the house during the holidays. Since landing in America in the colonial era, they have graced our landscapes, been used in instruments, and have become a noteworthy piece of holiday decor. It is a popular holiday tradition to weave sprigs of boxwood together to form wreaths, garland, swags, and small trees for Christmas displays. Live cut boxwood can last several weeks if properly preserved, making them perfect for the holiday season.

This is a specimen plant that has been used for wreath cuttings.

Boxwood will flush from the exposed stems,but will take a while to fill back in entirely.

Many growers have made an industry around this where they grow boxwood specimens to be used as cutting material in these decorative items. Large boxwood are trimmed drastically to provide the material. These branches are bagged and shipped around to different florists and designers who incorporate them into decorative pieces. Though it looks harsh, boxwood shrubs are very tolerant of pruning and will flush from the old exposed trunks, and eventually fill back in.  

It is important to remember when using boxwood in decorative items that the original plant is free of boxwood blight. Boxwood blight is a fungal pathogen with sticky spores that survive on desiccated boxwood leaves and branches. These spores can spread to healthy plants if they come in contact, or water splashes from the infected material to the healthy plant. If you are bringing home a beautiful new boxwood wreath, it is important to ask where the plant material came from and be sure it is free of boxwood blight. At a minimum, when the Christmas season comes to a close and it’s time to dispose of the wreath, do so in the garbage and do not compost or place near the boxwood in the landscape.

A truck filled with bags of Christmas greens, including boxwood.

Boxwood decorations have been a part of the Christmas decor for centuries and provide a way to bring parts of the outdoor landscape into the home to beautify any living space.

Dec. 2019: Boxwood Blight Update

A field of boxwood affected by Boxwood Blight.

Since its introduction to the United States in 2011, boxwood blight has been found in 26 states. Its affects have been seen from the Mid-Atlantic to the west coast in varying degrees. One of the biggest contributing factors to the prevalence and spread of this disease is climate. Boxwood blight requires specific environmental conditions which vary year to year. This fungal disease spreads by spores that move by water splashing, physical contact, or on debris. Infections occur during humid, warm periods, and can spread quickly when conditions are ideal.

The map above shows states with reported cases of Boxwood Blight by year.

Characteristic symptoms of Boxwood Bight include dark streaking on the branches, leaf spots, and defoliation.

As many growers recall, 2018 was a devastating year, especially in the Mid-Atlantic. With record breaking rainfall and extended periods of warm, wet weather, many growers, landscapers, and homeowners saw more cases of the disease than previous years. Mary Ann Hansen, who oversees the Virginia Tech Plant Disease Clinic reflects, “In 2018 when we had so much rain across the state, the VT Plant Disease Clinic received 188 boxwood samples that were positive for boxwood blight. This amounted to over 11% of our sample total.”

Bennett Saunders next to the Tye River at record high levels in September 2018 after another heavy rain storm.

In Piney River, VA we saw over 90 inches of rain throughout the year, compared to the annual average of about 45 inches. Reports of flooding and extended rain events throughout the spring, summer, and fall were followed by reports of infection.

Juxtaposed to the previous year, 2019 has been uncharacteristically dry, leading to fewer cases. Mary Ann from Virginia Tech reports, “In 2019, we only received 44 boxwood samples that were positive for boxwood blight, and this amounted to less than 3% of our total samples. The number of samples received by the Clinic doesn't necessarily represent the amount or severity of the disease across the state, but in this case, I think it probably did. The weather in 2018, especially in the fall, when boxwood blight tends to be a problem, was very conducive to boxwood blight, whereas the long drought and high temperatures in many areas of the state in 2019 were not conducive to boxwood blight. The fungal pathogen, Calonectria pseudonaviculata, does best at moderate temperatures with extended periods of leaf wetness.”

It is important to keep in mind the effect the environment can have on the spread of plant diseases. For more information on Boxwood Blight and how to prevent it, check out the Virginia Tech Boxwood Blight Task Force website or read more about it here.